Synchronous rectifying drive circuit with energy feedback for voltage doubler rectifer

1. A current-driven synchronous rectifying drive circuit designed for a T-type voltage doubler rectifier, the drive circuit comprising: a clamp and energy feedback circuit; a high frequency transformer, a current transducer; an energy storage capacitor; an output capacitor; a first and a second synchronous rectifier; and a first drive circuit connected to the first synchronous rectifier and a second drive circuit directly connected to the second synchronous rectifier; wherein a non-dotted terminal of the high frequency transformer being directly connected to a non-dotted terminal of a primary winding of the current transducer, a dotted terminal of the high-frequency transformer being directly connected to a positive terminal of the energy storage capacitor, a source of the first synchronous rectifier being directly connected to a negative terminal of the energy storage capacitor as well as a drain of the second synchronous rectifier, a drain of first synchronous rectifier being directly connected to a positive terminal of an output capacitor and a dotted terminal of the primary winding of the current transducer, a gate of first synchronous rectifier being directly connected to an output port of the first drive circuit, a negative terminal of the output capacitor being directly connected to a drain of second synchronous rectifier, and a gate of second synchronous rectifier being directly connected to an output port of the second drive circuit.

2. The current-driven synchronous rectifying drive circuit according to claim 1 , wherein the first drive circuit and the second drive circuit each individually comprise a signal shaping and reset circuit, a self-bias circuit and a push-pull driver.

3. The current-driven synchronous rectifying drive circuit according to claim 2 , wherein each signal shaping and reset circuit is provided to convert the respective synchronous rectifier current signal, which is detected by the current transducer, into a voltage signal and shape it into a pulse signal, and to enable the current transducer to reset when the current of the synchronous rectifier reaches to zero, wherein the input port of the signal shaping and reset circuit is connected to a secondary winding of current transducer and an output port is connected to an input port of a push-pull driver.

4. The current-driven synchronous rectifying drive circuit according to claim 1 , wherein the self-bias circuit is provided to store energy from the current transducer in the first capacitor in order to generate a voltage source which can regulate with load and power consumption of the drive circuits in connection with each synchronous rectifier wherein the complete drive circuit is biased, and wherein an input port of the self-bias circuit is connected to a secondary winding of the current transducer while an output port is connected to a push-pull driver.

5. The current-driven synchronous rectifying drive circuit according to claim 1 , wherein the push-pull driver is provided to amplify a drive signal generated by the signal shaping and reset circuit to drive the synchronous rectifiers, an input port of this circuit is connected to the signal shaping and reset circuit and an output is connected to a gate of the synchronous rectifier.

6. The current-driven synchronous rectifier as claimed in claim 1 , further comprising a clamp and energy feedback circuit which comprises a first diode and a second diode, an anode of both diodes are connected respectively to the output ports of the first drive circuit and the second drive circuit, a cathode of both diodes connected to a positive terminal of the energy storage capacitor.

7. The current-driven synchronous rectifier as claimed in claim 6 , further comprising a signal shaping and reset circuit comprising a first diode (D 1 ), a second diode (D 2 ), a third diode (D 3 ), a resistor (R 1 ), and a NPN transistor (Q 1 ), wherein a cathode of the first diode (D 1 ) is connected to a dotted terminal of a secondary winding (N 2 ) of the current transducer and to a collector of the transistor (Q 1 ), an anode of the first diode (D 1 ) is connected to a first node of the resistor (R 1 ), a base of the transistor (Q 1 ), and to an anode of the second diode (D 2 ), a second node of the resistor (R 1 ) is connected to cathodes of the second and third diodes (D 2 and D 3 ) and to a non-dotted terminal of a secondary winding (N 2 ) of the current transducer, an anode of third diode (D 3 ) is connected to an emitter of the transistor (Q 1 ), wherein a push-pull driver comprises a NPN transistor (Q 2 ), a PNP transistor (Q 3 ), and a second resistor (R 2 ), a base of a second transistor (Q 2 ) is connected to a base of a third transistor (Q 3 ) and a node of the second resistor (R 2 ), a second node of the second resistor (R 2 ) is connected to a dotted terminal of a secondary winding (N 2 ) of the current transducer, an emitter of the second transistor (Q 2 ) is connected to an emitter of the third transistor (Q 3 ) and a gate of first synchronous rectifier, a collector of the third transistor (Q 3 ) is connected to an anode of the third diode (D 3 ), wherein a self-bias circuit comprises a fourth diode (D 4 ) and a third energy storage capacitor (C 3 ), an anode of the fourth diode (D 4 ) is connected to a collector of the transistor (Q 1 ), a cathode of the fourth diode (D 4 ) is connected to a positive terminal of the third energy storage capacitor (C 3 ) and a collector of the second transistor (Q 2 ), and a negative terminal of the third energy storage capacitor (C 3 ) is connected to a collector of a third transistor (Q 3 ).

8. The current-driven synchronous rectifier as claimed in claim 1 , further comprising a clamp and energy feedback circuit which is a MOSFET energy feedback circuit provided for a voltage doubler rectifying circuit comprising a commonly seen voltage doubler rectify where the MOSFET energy feedback circuit comprises a N-channel MOSFET (S 1 ), a first resistor (R 7 ), a second resistor (R 8 ), a third resistor (R 9 ), a fourth resistor (R 10 ), a capacitor (C 5 ), a diode (D 13 ) and a transistor (Q 9 ), a source of the N-channel MOSFET (S 1 ) is connected to a first node of the fourth resistor (R 10 ), a drain of the N-channel MOSFET (S 1 ) is connected to a positive terminal of the energy storage capacitor (C 3 ), a gate of the N-channel MOSFET (S 1 ) is connected to a collector of the transistor (Q 9 ), a second node of the fourth resistor (R 10 ) is connected to a positive terminal of the energy storage capacitor (C 4 ), an emitter of the transistor (Q 9 ) is connected to a source of the second synchronous rectifier (SR 2 ), a base of the transistor (Q 9 ) is connected to an anode of the diode (D 13 ), an cathode of the diode (D 13 ) is connected to a source of first synchronous rectifier (SR 1 ), a firsts node of the capacitor (C 5 ) and a first node of the second resistor (R 8 ) are connected to an anode of the diode (D 13 ), a second node of bother the capacitor (C 5 ) and the second resistor (R 8 ) are connected to an cathode of the diode (D 13 ), a first node of the third resistor (R 9 ) is connected to a source of N-channel MOS (S 1 ), a second node of the third resistor (R 9 ) is connected to a gate of N-channel MOSFET (S 1 ), a first node of the first resistor (R 7 ) is connected to a drain of the first synchronous rectifier (SR 1 ), and a second node of the first resistor (R 7 ) is connected to the gate of N-channel MOSFET (S 1 ).

9. The current-driven synchronous rectifier as claimed in claim 1 , wherein when one channel current transducer is provided, locating a protecting circuit between the drain and a source of each synchronous rectifier preventing a false drive signal, wherein the protecting circuit consists of a resistor, a diode and a transistor with a first node of the resistor connected to a cathode of the diode and the drain of the first synchronous rectifier, a second node of the resistor connected to a anode of the diode and a base of the transistor, a collector of the transistor connected to the drive circuit, and a emitter of the transistor connected to a source of the first synchronous rectifier.

10. The current-driven synchronous rectifier as claimed in claim 6 , wherein when one channel current transducer is provided, locating a protecting circuit between the drain and a source of each synchronous rectifier preventing a false drive signal, wherein the protecting circuit consists of a resistor, a diode and a transistor with a first node of the resistor connected to a cathode of the diode and the drain of the first synchronous rectifier, a second node of the resistor connected to a anode of the diode and a base of the transistor, a collector of the transistor connected to the drive circuit, and a emitter of the transistor connected to a source of the first synchronous rectifier.

11. The current-driven synchronous rectifier as claimed in claim 7 , wherein when one channel current transducer is provided, locating a protecting circuit between the drain and a source of each synchronous rectifier preventing a false drive signal, wherein the protecting circuit consists of a resistor, a diode and a transistor with a first node of the resistor connected to a cathode of the diode and the drain of the first synchronous rectifier, a second node of the resistor connected to a anode of the diode and a base of the transistor, a collector of the transistor connected to the drive circuit, and a emitter of the transistor connected to a source of the first synchronous rectifier.

12. The current-driven synchronous rectifier as claimed in claim 8 , wherein when one channel current transducer is provided, locating a protecting circuit between the drain and a source of each synchronous rectifier preventing a false drive signal, wherein the protecting circuit consists of a resistor, a diode and a transistor with a first node of the resistor connected to a cathode of the diode and the drain of the first synchronous rectifier, a second node of the resistor connected to a anode of the diode and a base of the transistor, a collector of the transistor connected to the drive circuit, and a emitter of the transistor connected to a source of the first synchronous rectifier.

13. A current-driven synchronous rectifying drive circuit designed for a T-type voltage doubler rectifier, the drive circuit comprising: a clamp and energy feedback circuit; a high frequency transformer, a current transducer; an energy storage capacitor; an output capacitor; a first and a second synchronous rectifier; a first drive circuit connected to the first synchronous rectifier and a second drive circuit connected to the second synchronous rectifier; and a second current transducer; wherein a non-dotted terminal of the high frequency transformer being directly connected to a drain of the first synchronous rectifier and a positive terminal of the output capacitor, a dotted terminal of the high frequency transformer being directly connected to a positive terminal of the energy storage capacitor; a source of the first synchronous rectifier being directly connected to a non-dotted terminal of a primary winding of the current transducer; a gate of the first synchronous rectifier being directly connected to an output port of the first drive circuit, a drain of the second synchronous rectifier being directly connected to a dotted terminal of a primary winding of the second current transducer; a source of the second synchronous rectifier being directly connected to a negative terminal of the output capacitor, a gate of second synchronous rectifier directly connected to the output port of its drive circuit; and a negative terminal of the energy storage capacitor is directly connected to a dotted terminal of a primary winding of the first current transducer and to a non-dotted terminal of the primary winding of the second current transducer.

14. The current-driven synchronous rectifying drive circuit according to claim 13 , wherein the first drive circuit and the second drive circuit each individually comprise a signal shaping and reset circuit, a self-bias circuit and a push-pull driver.

15. The current-driven synchronous rectifying drive circuit according to claim 14 , wherein each signal shaping and reset circuit is provided to convert the respective synchronous rectifier current signal, which is detected by the current transducer, into a voltage signal and shape it into a pulse signal, and to enable the current transducer to reset when the current of the synchronous rectifier reaches to zero, wherein the input port of the signal shaping and reset circuit is connected to a secondary winding of current transducer and an output port is connected to an input port of a push-pull driver.

16. The current-driven synchronous rectifying drive circuit according to claim 14 , wherein the self-bias circuit is provided to store energy from the current transducer in the first capacitor in order to generate a voltage source which can regulate with load and power consumption of the drive circuits in connection with each synchronous rectifier wherein the complete drive circuit is biased, and wherein an input port of the self-bias circuit is connected to a secondary winding of the current transducer while an output port is connected to a push-pull driver.

17. The current-driven synchronous rectifying drive circuit according to claim 14 , wherein a push-pull driver is provided to amplify a drive signal generated by the signal shaping and reset circuit to drive the synchronous rectifiers, an input port of this circuit is connected to the signal shaping and reset circuit and an output is connected to a gate of the synchronous rectifier.

18. The current-driven synchronous rectifier as claimed in claim 13 , further comprises a clamp and energy feedback circuit which comprises a first diode and a second diode, an anode of both diodes are connected respectively to the output ports of the first drive circuit and the second drive circuit, a cathode of both diodes connected to a positive terminal of the energy storage capacitor.

19. The current-driven synchronous rectifier as claimed in claim 18 , further comprising a signal shaping and reset circuit comprising a first diode (D 1 ), a second diode (D 2 ), a third diode (D 3 ), a resistor (R 1 ), and a NPN transistor (Q 1 ), wherein a cathode of the first diode (D 1 ) is connected to a dotted terminal of a secondary winding (N 2 ) of the current transducer and to a collector of the transistor (Q 1 ), an anode of the first diode (D 1 ) is connected to a first node of the resistor (R 1 ), a base of the transistor (Q 1 ), and to an anode of the second diode (D 2 ), a second node of the resistor (R 1 ) is connected to cathodes of the second and third diodes (D 2 and D 3 ) and to a non-dotted terminal of a secondary winding (N 2 ) of the current transducer, an anode of third diode (D 3 ) is connected to an emitter of the transistor (Q 1 ), wherein a push-pull driver comprises a NPN transistor (Q 2 ), a PNP transistor (Q 3 ), and a second resistor (R 2 ), a base of a second transistor (Q 2 ) is connected to a base of a third transistor (Q 3 ) and a node of the second resistor (R 2 ), a second node of the second resistor (R 2 ) is connected to a dotted terminal of a secondary winding (N 2 ) of the current transducer, an emitter of the second transistor (Q 2 ) is connected to an emitter of the third transistor (Q 3 ) and a gate of first synchronous rectifier, a collector of the third transistor (Q 3 ) is connected to an anode of the third diode (D 3 ), wherein a self-bias circuit comprises a fourth diode (D 4 ) and a third energy storage capacitor (C 3 ), an anode of the fourth diode (D 4 ) is connected to a collector of the transistor (Q 1 ), a cathode of the fourth diode (D 4 ) is connected to a positive terminal of the third energy storage capacitor (C 3 ) and a collector of the second transistor (Q 2 ), and a negative terminal of the third energy storage capacitor (C 3 ) is connected to a collector of a third transistor (Q 3 ).

20. The current-driven synchronous rectifier as claimed in claim 13 , further comprising a clamp and energy feedback circuit which is a MOSFET energy feedback circuit provided for a voltage doubler rectifying circuit comprising a commonly seen voltage doubler rectify where the MOSFET energy feedback circuit comprises a N-channel MOSFET (S 1 ), a first resistor (R 7 ), a second resistor (R 8 ), a third resistor (R 9 ), a fourth resistor (R 10 ), a capacitor (C 5 ), a diode (D 13 ) and a transistor (Q 9 ), a source of the N-channel MOSFET (S 1 ) is connected to a first node of the fourth resistor (R 10 ), a drain of the N-channel MOSFET (S 1 ) is connected to a positive terminal of the energy storage capacitor (C 3 ), a gate of the N-channel MOSFET (S 1 ) is connected to a collector of the transistor (Q 9 ), a second node of the fourth resistor (R 10 ) is connected to a positive terminal of the energy storage capacitor (C 4 ), an emitter of the transistor (Q 9 ) is connected to a source of the second synchronous rectifier (SR 2 ), a base of the transistor (Q 9 ) is connected to an anode of the diode (D 13 ), an cathode of the diode (D 13 ) is connected to a source of first synchronous rectifier (SR 1 ), a firsts node of the capacitor (C 5 ) and a first node of the second resistor (R 8 ) are connected to an anode of the diode (D 13 ), a second node of bother the capacitor (C 5 ) and the second resistor (R 8 ) are connected to an cathode of the diode (D 13 ), a first node of the third resistor (R 9 ) is connected to a source of N-channel MOSFET (S 1 ), a second node of the third resistor (R 9 ) is connected to a gate of N-channel MOSFET (S 1 ), a first node of the first resistor (R 7 ) is connected to a drain of the first synchronous rectifier (SR 1 ), and a second node of the first resistor (R 7 ) is connected to the gate of N-channel MOSFET (S 1 ).